This article reviewed a two-center study using aortic valve morphologic features to discriminate between valves that respond favorably or unfavorably to balloon aortic valvuloplasty (BAV), using aortic insufficiency (AI) as the primary outcome. Morphologic features assessed on pre-BAV echo included: valve pattern (unicuspid, functional bicuspid, and true bicuspid), leaflet fusion length, leaflet excursion angle, and aortic valve opening area. On post-BAV echo, morphologic features included leaflet versus commissural tear. The primary endpoint was an increase in AI (AID) of ≥2. Of the 49 patients (median age 0.2 years), 39 unicuspid, 41 functional bicuspid, and nine true bicuspid valves. Unicuspid valves had a lower opening area (p <0.01) and greater fusion length (p [ 0.01) compared with functional and true bicuspid valves. Valve gradient pre-BAV and post-BAV were not different among valve patterns. Of the 16 patients (18%) with AID, 14 had leaflet tears (odds ratio 13.9, 3.8 to 50). True bicuspid valves had the highest rate (33%) of AID. On multivariate analysis, leaflet tears were associated with AID, with larger opening area pre- BAV and lower fusion length pre-BAV. AID was associated with a larger pre-BAV opening area. Gradient relief was associated with a reduced angle of excursion. Valve morphology influences outcomes after BAV. Valves with lesser fusion and larger valve openings have higher rates of leaflet tears which in turn are associated with AI. The authors hypothesized that greater preintervention anatomic characterization of the aortic valve would allow for enhanced patient selection, which ultimately may result in improved outcomes after BAV. Patients who present as neonates with AS appear to be at the highest risk of repeat interventions, including repeat valvuloplasty, surgical valve repair, and aortic valve replacement. But even in the neonates, most studies have demonstrated a subset of the cohort which remains intervention-free 10-20 years after initial valvuloplasty. Relief of valve gradient was related directly to aortic valve characteristics. The data suggest that limited valve leaflet mobility pre-BAV, measured by a lower angle of excursion, was associated with a better rate of gradient relief. These data further indicate that valves with smaller valve opening areas, greater fusion, and decreased mobility may favor BAV. These findings suggest that aortic valve characteristics should figure prominently in the selection criteria for surgical versus transcatheter intervention.   

All editors: Frank F. Ing, MD, MSCAI